Semiconductor fabrication processes involve fabricating several thousand individual devices on one wafer. Specifically, semiconductor wafers are cleaved to form chips, die, pieces and bars, which are later used in electronics and computer devices. After cleaving, the semiconductor chips are coated and are ready for further processing or storage. Due to the small size and delicate nature of the semiconductor chips, particularly careful storage procedures are required to prevent damage such as chipping or breaking.
Currently, a number of devices and methods are employed in handling and storing semiconductor chips. One such device involves the use of carrier trays having a plurality of cavities. Each cavity holds one semiconductor chip in place. There are numerous disadvantages to this method of storage. First, the size of the cavities must match closely with the size of the semiconductor chips to be stored so that the semiconductor chips do not fall out or move around within the cavity. Therefore, containers with different sized cavities are necessary to accommodate different size semiconductor chips. Often, in cases where a custom container for a particular semiconductor chip is not available, a custom fit container for a different size semiconductor chip will be used. In this situation, if the size of the cavity does not match closely with the semiconductor chips to be stored, the semiconductor chips will turn over within the cavity. This problem is time consuming and costly because each semiconductor chip must then be reoriented. Moreover, the semiconductor chips tend to break if there is room for them to move around the cavity. Finally, if particular care is not taken when the cavity tray is opened, the semiconductor chips will fall out resulting in the total destruction of the semiconductor chip.
Another device currently used for storing semiconductor chips is similar to the aforementioned device but further employs mechanical retaining members to help secure the chips in the cavities. While the mechanical retaining members alleviate some of the above mentioned problems, new problems are created. The mechanical retaining member must be customized to the size of the particular semiconductor chip being stored. Numerous mechanical retaining members are, therefore, needed. Furthermore, because of the delicate nature of the semiconductor chip, the retaining member must be carefully designed to prevent the retaining member from causing damage to the semiconductor chip. This results in additional design cost.
Another method of storing semiconductor chips employs an adhesive layer to retain the semiconductor chips in position, rather than a mechanical member. Current methods utilize pressure sensitive adhesive devices which use vacuum and porous film. Often, however, the adhesive sticks to the semiconductor chip after it has been removed causing serious damage. In addition, the level of adhesion tends to change over time and with ambient conditions. This causes the semiconductor chips to fall out of the device in cases where the adhesion decreases. Conversely, when the adhesion level increases, a higher level of force is required to remove the chips, increasing the likelihood of breakage.
In each of the above devices, an ejector pin is used to remove the semiconductor chips from the cavities. Due to the delicate nature of the semiconductor chips, the use of ejector pins can result in great damage to the chips.